Process for producing alkali-metal xanthates



Patented Oct. 27, 1925.

UNITED STATES PATENT OFFICE.

RUSSELL B. CROWELL, 0F AGNEW, AND GERALD F. BRECKENRIDGE, OF SAN JOSE, CALIFORNIA, ASSIGNORS TO WESTERN INDUSTRIES COMPANY, OF AGNEW, CALI- FORNIA, A CORPORATION OF CALIFORNIA.

PROCESS FOR PRODUCING ALKALI-METAL XANTHATES.

No Drawing.

To all whom it may concern Be it known that Rossnnr. B. Cnownuf and GERALD F. BRECKENRIDGE, citizens of the United States, residing at Agnew and San Jose, in the'county of Santa Clara and State of California, respectively, have invented the Process for Producing Alkali- Metal Xanthates, of which the following is a specification.

This invention relates to processes of producing salts of xanthic or ethyloxydithiocarbonic acid of the alkali metals such as sodium or potassium.

It has been proposed to produce the alkali metal Xanthates such as sodium or potassium Xanthates by causing a reaction to take place between a hydroxide of the alkali metals such as sodiumor potassium, carbon bisulphide. and ethyl alcohol, the reaction being carried out either in the presence of an aqueous medium or in the presence of an excess of alcohol. In processes wherein this reaction is carried out in an aqueous medium the water has the effect of materially reducing the percentage yield of the Xanthate salts thereby causing an increase in the cost thereof. Processes in which the reaction takes place in the presence of an cxcessof alcohol present the disadvantage that the alcohol utilized in the process is either lost or is recovered only with great difficulty therefrom, thereby causing such processes to be necessarily costly. Another known process of thate is that in which the metal sodium is dissolved in dry alcohol, and to this solution is added a calculated quantity of dry carbon bisulphide, the reacting mixture being continuously cooled and agitated until the reaction is complete.

Accordingly, one of the objects of this invention is to provide an improved process of producing, alkali metal xanthates wherein a mixture of a hydroxide ot'an alkali metal, carbon l'iisulphide, and alcohol are reacted in the absence of either an aqueous medium or an excess of alcohol.

'Another object of this invention is to provide an improved method of producing the salts of xanthic acid of the alkali metals which results in a high percentage yield of such salts in a substantially purer state and at lower cost than is the case in the processes of the prior art.

well i'roducin sodium xan-- Application filed May 18, 1325. Serial No. 31,203.

Other and further objects of this invent on will appear from the more detailed description of this invention set forth hereinafter, it being understood that various changes may be made therein by those skilled in the artwithout/ departing from the scope and spirit of this invention as defined in the appended claims.

In one preferred embodiment of carrying out our invention we take either anhydrous sodium or potassium hydroxide, the choice of the hydroxide being dependent upon which one of the particularxanthate salts of the alkali metals is desired, in amounts equivalent to their molecular weights and grind or reduce the same to a ranular or powdered state with the partic es of such size that the crushed material will pass through a screen of 80 mesh or greater. This pulverulent anhydrous material is then admixed with a hydrocarbon liquid body as kerosene, gasolene, toluene, or asimilar liquid which possesses the inherent property of being chemically inert to such hydroxides, under vigorous agitation. As soon as the hydroxide is thoroughly disseminated throughout the bodyof hydrocarbon liquid and while the hydroxide hydrocarbon mixture is being vigorously agitated, ethyl alcohol or commercial alcohol in an amount corresponding to its molecular weight is added thereto. Upon contact of'the alcohol with hydroxide hydrocarbon mixture, heat is evolved and a semi-colloidal suspensoid having the appearance of a gel-like precipitate is formed. To this sus ensoid mixture is then added gradually an slowly, carbon bi-sulphide in amount equivalent to its molecular weight. While the. carbon bisulphide is being added to the mixture containing the suspensoid, the reacting mass is cooled and simultaneously subjected to vigorous agitation, such a itation and cooling being continued until t e reaction is comsimilar liquids, the mixture then vigorously stirred until a suspensoid of the hydroxide in a liquid nonaqueous medium is produced, and then adding to the suspensoid mass a mixture consisting at alcohol and carbon bisulphide in amounts equivalent to their molecular Weights, the whole mass being vigorously agitated and cooled during the reaction. The procedure may be further modified by adding a part of the requisite amount of alcohol to thehydroxide suspensoid mixture, and a part of the alcohol to the requisite amount of carbon bisulphide, and then bringing the two portions together under vigorous agitation in a vessel provided with suitable cooling means through which an appropriate cooling medium is caused to circulate, during; the interval in which the mass reacts and the reaction is completed.

' The percentage yield of the xanthate i salts of the alkali metals as. sodium or potassium produced by the processes hereinabove set forth is high, and such salts are in a substantially pure state. The xanthate salts may be readily recovered from the re acted mass. and ,may be dried in the usual manner or if desired for immediate use may be dissolved in water.

Having: described our invention, what we claim as new and desire to secure by Letters Patent is 1. The process of producing: alkali metal xanthates which comprises reacting a hydroxide of an alkali-metal, alcohol, and car.- bon bisulphide. in a. liquid hydrocarbon medium chemically inert to the remaining informing a suspension of an anhydrous alliali-metal hydroxide in a liquid hydrocarbon medium chemically inert to said by dioxide, and adding alcohol thereto.

4. In the process of producing alkalimetal xanthutes the steps which comprise forming a suspension of an alkali-metal hydroxide .in a liquid hydrocarbon medium chemically inert to said hydroxide and adding alcohol and carbon bisulphide thereto.

5. In the process of producing alkalimetal Xanthates the steps which comprise forming asuspension of anhydrous alkalimetal hydroxide in a liquid hydrocarbon inediunrchmically inert to the said hydroxide, adding alcohol thereto, and then adding carbon bisulphide.

6. The process of providing alkali metal xanthateswhich comprises forming a suspension of an alkali metal hydroxide in a liquid hydorcarbon chemically inert to said hydroxide, adding alcohol thereto, and then adding: a mixture of alcohol-and carbon'bisulphide to the alcohol hydroxide rnixture.

7. The process as set forth'in claim 6 wherein the hydroxide suspension is subjected to agitation during the addition of the alcohol thereto.

8. The process as' set forth .in claim wherein the alcohol hydroxide mixture 'is cooled and vigorously agitated during the addition of the mixture of alcohol and carbon bisulphide'thereto.

9. The process of producing alkali metal xanthates which comprises forming a suspension of an alkalimetal hydroxide in a liquid hydrocarbon chemically inert to said hydroxide, adding alcohol thereto, ,cooling the mixture. adding carbon bisulphi'de, and recovering the salt thus produced.

10. The process of roducing' alkali metal xanthates which consists in forming a 'suspension of an alkali metal hydroxide in a liquid hydrocarbon chemically inert to said hydroxide, adding alcohol thereto, cooling the mixture, adding an admixture of alcohol and carbon hisulphide tosaid mixture. and recovering the salts thus produced. j

In testimony whereof we afiix our signa tures.

EUSSELL -B. CROVVELL. GERALD F. BRECKENRIDGE. 

